Closure means for liquid tight cartons



y 9, 1951 F. D. BERGSTEIN 2,983,419

CLOSURE MEANS FOR LIQUID TIGHT CARTONS 2 Sheets-Sheet 1 Filed March 10. 1953 INVENTOR. fIfA/V .D. .Bsras ram ziww ATTORNEYS.

y 1961 F. D. BERGSTEIN 2,983,419

CLOSURE MEANS FOR LIQUID TIGHT CARTONS Filed March 10, 1955 2 Sheets-Shet 2 INVENTOR. fkmvk .D. BEeGSTE/ ATTORNEYS.

United States Patent 9 Bergstein Packaging Trust, a trust composed at" Rabert M. Bergsteiu and Frank D. Bergstein, trustees Filed Mar. 10, 1953, Ser. No. 341,525

2 Claims. (Cl. 229-7) My invention relates to liquid tight cartons, and more particularly to reclosable closure means for such cartons. Cartons to which this invention relates will find their principal usefulness as containers for milk and the like requiring a reclosable pouring opening.

It is a principal object of my invention to provide liquid tight cartons having a pouring opening formed in the top wall thereof, which pouring opening is closed by means of a closure element including a plug-like membet for insertion in the pouring opening.

It is a further object of my invention to provide a liquid tight carton of the character described wherein the inner surfaces of the carton end walls are sealed by means of relatively thick layers of thermoplastic sealing substance, there being a pouring opening extending rough one end of the carton and the layer of sealing substance, the openings so for-med being closed by means of a plug of thermoplastic sealing substance carried by a closure element secured to the carton adjacent the pourin-g opening.

Still another object of my invention is the provision of a closure element for a carton of the character described wherein the closure element includes a foil sheet hingedly secured to the carton end and having portions thereof adapted to be folded down about the edges of a plurality of adjacent body walls of the carton.

Yet another object of my invention is the provision of a closure element including a piece of foil secured to the carton end so as to be hingedly connected thereto, the closure element being adapted to pivot along a hinge line in the foil.

These and other objects of my invention which will. appear hereinafter or will be apparent to a skilled worker in the art upon reading these specifications, I accomplish by means of those constructions and arrangements of parts of which I shall now describe certain exemplary embodiments.

Reference is now made to the drawings forming a part of this specification, and wherein:

Figure l is a partial perspective view of a carton inaccordance with my invention and a piece of foil to be associated therewith to form the closure element.

Figure 2 is a perspective view similar to Figure 1 but showing the piece of foil associated with the carton end.

Figure 3 is also a partial perspective view of the carton end and shows the foil piece in the formed condition.

Figure 4 is a sectional View taken along the line 44 of Figure 3.

Figure 5 is a partial perspective view similar to Figure 4 showing the closure element in the raised position.

Figure 6 is a partial plan view of a carton blank in accordance with my invention.

Figure 7 is a partial perspective view showing the blank of Figure 6 in erected condition.

Figure 8 is a vertical sectional view illustrating the manner in which the carton ends are sealed by means of a layer of thermoplastic material.

Figure 9 is a partial plan view of a carton blank whereend closure flaps.

Patented May'9, 1961 in the foil piece has been applied to the blank while in flat condition.

Figure 10 is au enlarged fragmentary view of the outermost flap of a carton configured to provide. a closure element surfaced on its under side with a piece of foil.

Figure 11 is a partial perspective view of a carton formed from a blank including the outermost flap of Figure 10. V

Figure 12 is a partial vertical section illustrating the manner in which the carton of Figure 11 is sealed.

Figure 13 is a partial perspective View of the carton of Figure 11 with theextending edges of the foil folded down about the carton side walls. i I

Figure 14 is a sectional view taken along the line 1414 ofFigure l3. I

Figure 15 is a partial perspective view of the end closure of Figure 13 in the raised position.

Figure 16 is a partial perspective view of an end closure construction similar to Figure 13 but with the foil to the outside. I I

, Figure 17 is a sectional view taken along the line 1717 of Figure l I I Figure 18 is a sectional view similar to Figure 17 illustrating a modified closure element.

Figure 19 is a partial perspective view of the closure element of Figure 18 in the raised position.

I In the practice of myinvention, I provide a knockdown carton having the desired proofed characteristics as to its body walls. Upon erection of the carton structure, I then effect a seal on the inside of the carton across one or both ends thereof. For details relative to the formation of cartons having such .end seals, reference is made to my Patents No. 2,543,757, 2,549,048, and 2,604,252. In accordance with the teachings herein, 1 am enabled to provide such liquid tight carton structures with. improved and highly advantageous reclosable pouring openmgs.

Referring first to Figure 6, I have shown a blank for an exemplary carton having a series of body walls 1, 2, 3, and 4 in articulation in the order named, and a 'glue flap 5 articulated to body wall At the tops of the body walls I provide closure flaps 6, 7, 8, and 9 which are seal- In the embodiment illustrated, the flaps 7 and 9 are of lesser area than the remaining two flaps and are designed to be infolded first. Flap 7 is provided with an opening 10 which registers with an opening 11 in the intermediate flap 8. Similarly, the outerrnost flap 6 is provided with a mating opening 12.

It will be understood that the body walls 1 to '4 of the carton will be provided at their bottom ends with suitable closure flaps, preferably of the seal-end variety also. The carton will be made of boxboard or paperboard suitably proofed in view of the nature of the liquid which is to be transported in it; or, instead of proofing the board, the body walls may be lined with a suitably proofed liner. The nature of the proofing does not, however, form a limitation upon this invention.

The carton blank may be tubed in the ordinary way through the use of conventional carton folding and gluing equipment. The adhesive used in tubing the carton will preferably be one uneifected by the nature of the liquid to be transported. Generally speaking, the tubed, knocked-down structure will be shipped to the carton user; although, as will appear hereinafter, the foil incorporated in the closure element may be, under certain circumstances, applied to the carton by the manufacturer.

The carton user will erect the carton in the customary way, and will first close the flaps onthe top end thereof, the flaps being folded with the interposition of a suitable adhesive. The top end of the carton thus'assumes the condition illustrated in Figure 7 of the drawings.

After the carton has been closed on the top end, it

is then inverted and sealed on that end. This may be done in the manner illustrated in Figure 8, wherein a liquid sealing substance 13 is introduced into the carton by a spout 14. In the embodiment illustrated, the pouring opening defined by the openings 11), 11 and 12 is temporarily closed by a plug 15 forming a part of sup porting jig 16. The plug 15 results in the definition of a pouring opening extending through the layer of sealing substance covering the interior end of the carton. The nature of the sealing substance used to cover the carton end is not a specific limitation upon my invention.

The carton is next closed upon the opposite end, by the interfolding and adhesive securement of the remaining closure flaps in the usual way and with the usual apparatus while the carton is in the position illustrated in Figure 8.

The carton is next up-ended for the introduction of sealing substance into the opposite end thereof and the application of the closure element covering the pouring opening. New sealing substance for the opposite end will be introduced into the carton through the pouring opening preferably prior to the application of the closure element.

As seen in Figure 1, the closure elements comprise a fiat sheet of foil 17 of a size to cover the pouring opening 18 and approximately one quarter of the carton top, it being noted that the pouring opening 18 is positioned adjacent one corner of the carton top. The piece of foil 17 is preferably secured to the uppermost flap 6 by means of a spot of adhesive 19, which is preferably of triangular configuration and positioned as illustrated. The piece of foil is adhesively secured to the carton top in the manner illustrated in Figure 2 with the edges 29 and 21 of the foil extending somewhat beyond the corresponding edges of the carton. While I have illustrated the spot of adhesive as being applied to the carton top, it will be readily apparent that the adhesive may be applied to the foil.

In an exemplary embodiment, the pouring opening is one inch in diameter and spaced approximately one fourth of an inch from the adjacent side Walls; and the foil sheet is a two-inch square extending beyond the carton edges approximately three-eights of an inch along two adjacent sides thereof.

Following application of the foil, the plug like portion 22 may be formed in the foil by means of a suitably shaped die. To this end the opening 18 may be utilized as a mold block or female die cavity. The extending edges and 21 of the foil are also infolded to lie along the adjacent side walls 2 and 3, the foil sheet being creased along the edges of the carton top. The extending tip 23 is then folded to lie along one of the edge portions, in the manner illustrated in Figure 3. It will be understood that the foil pieces may be preformed in whole or in part and supplied individually or in strip form if so desired.

The construction just described results in a very neat and quite inexpensive closure for the pouring opening. As seen in Figure 4, the plug-like portion 22 enters the pouring opening and contacts the interior end-seal 24 forming a tight closure therewith. The remainder of the foil covers and protects the areas immediately surrounding the pouring opening, and the folded edge portions 20 and 21 cover and protect the adjacent edges of the carton walls, which is an essential in the provision of a sanitary carton for use as a container for milk.

The carton is easily opened, the user simply having to press upwardly against the edges 20 and '21 to raise the cover element for pouring purposes. The foil closure provides its own hinge, folding along the line of fold 25 in the manner best seen in Figure 5, the line of fold 25 being defined by the edge 25a of the adhesive spot 19. The foil element readily folds down again as a reclosure and may be opened and closed a number of times. Slight inward pressure against the edges 20 and 21 during reclosing will assure gripping contact of those parts 'with the body walls of the carton, thereby assuring the maintenance of the closure element in the closed position.

While the specific nature of the foil sheet does not constitute a limitation of my invention, I have found aluminum foil of .003 inch in thickness to be highly satisfactory.

In Figure 9, I have illustrated a carton blank similar to the blank of Figure 6 excepting that the opening 12 has been eliminated from the closure flap 6 and the closure flap configured to provide a flap portion 26 adapted to be folded relative to the flap 6 along the line line of fold 27. The flap portion 26 is covered on its outer surface by the foil piece 17 which projects therebeyond to again form the extending or edge portions 2s and 21. The foil 17 is preferably secured to the flap portion 26 by means of a suitable adhesive, and the foil may be applied to the carton blank before or after tubing, as in the manner illustrated in Figures 9 and 10.

When the blank of Figure 9 is erected and the end closure formed, the carton assumes the condition illustrated in Figure 11. In this condition it will be noted that the foil lies between the flap portion 26 and the underlying, intermediate fiap 8 and covers the pouring opening 18. Thus, when the carton is inverted and the sealing material is introduced therein by means of the nozzle 14, as seen in Figure 12, the sealing substance not only covers the inner surface of the closed end but also enters the opening 18 and contacts the exposed portion of the foil. Then, after the sealing substance has set sufiiciently so that the sealing substance will not flow, the carton is uprighted and the extending edge portions 29 and 21 folded down to the position illustrated in Figure 13.

The carton is opened by lifting the flap portion 26, which may be accomplished by pushing upwardly on the folded edge portions 26 and 21 of the foil, as before. The result of lifting the flap 26 is to open up the pouring opening 18, the sealing substance formerly extending over this opening interiorly of the carton breaking away and coming out a plug 22a in adhesive union with the foil carried on the under surface of the flap portion 26. The lifted closure flap is seen in Figure 15 of the drawings. As before, the carton may be reclosed by folding the flap portion into its original position.

The construction just described results in a closure in which the foil is both reinforced and protected exteriorly by the flap portion 26. In addition, the construction provides an uninterrupted top surface for the carton; and the foil acts as a hinge for the folding of the flap portion 26 along the fold line 27. The fold line 27 thus may be materially weakened, as by the line of cut 27a (Fig. 10) to minimize the normal spring-back tendency of the boxboard when folded without decreasing the ability of the parts to be repeatedly folded and unfolded. Also, the normal tendency of the foil to remain in a given folded position, i.e., its dead folding characteristic, acts to maintain the flap portion 26 in a given folded condition.

In Figure 16, I have illustrated a modification of my invention wherein the foil sheet 17 overlies the flap portion 26 rather than lying between it and the intermediate flap 8. In this instance the quantity of sealing substance 24 entering the pouring opening 18, comes in direct contact with the flap portion 26 rather than in contact with the foil 17. The foil, however, affords the same protective and hinging functions as before.

Figures 18 and 19 illustrate yet another modification of my invention which in many respects is similar to that illustrated in Figures 1 through 5. However, in this instance the sealing substance is introduced into the carton end in the manner shown in Figure 12 so as to form a plug of adhesive substance in contact with the foil sheet; and upon opening of the carton by upward movement of the foil, the plug 22a breaks away from i the layer of sealing substance 24 to define the pouring opening 18, in the manner shown in Figure 19 of the drawings.

It can be pointed out in connection with those modifications of my invention employing a plug composed of sealing substance, that following initial opening of the car-ton, it may be reclosed with the application of heat in a quantity sufficient to cause the plug portion 22a to fuse with the layer of sealing substance 24 to again completely seal the carton. Of course, for normal household usage, the mere closing of the closure element will suffice.

Modifications my be made in my invention without departing from the spirit of it. Having, however, de-

scribed my invention in certain exemplary embodiments, what I claim is new and desire to secure by Letters Patent is:

1. In a container having a top Wall composed of a plurality of closure flaps including an inner closure flap having a pouring opening formed therein adjacent a corner edge of the container and an outer closure flap having 'a liftable portion overlying said pouring opening, said liftable portion being hingedly connected to said outer closure flap along a line of fold spaced inwardly from said pouring opening and diagonally disposed with respect to the edges of said top wall adjacent said pouring opening, said last named'edges of said top wall defining a pouring lip for the container, the outer edges of said liftable portion coinciding with the said last named edges of said top wall and an initially flat reotangular sheet of foil having dead-folding characteristics secured to said liftable portion with one corner thereof extending inwardly across the line of fold hingedly connecting said liftable portion to said outer closure flap, the extending corner of said foil sheet being secured beyond said line of fold, whereby said sheet of foil will be caused to fold along said line of fold when said liftable portion is raised and lowered and the dead-folding characteristics of said foil will be imparted to said liftable portion, the edges of said sheet of foil opposite the hinged corner thereof extending outwardly beyond the outer edges of said liftable portion to define flanges, said flanges being folded downwardly and juxtaposed to marginal edge portions of the adjoining container body walls, the downwardly folded flanges defining between them an extending gusset at the corner of the container which is folded to lie along one of the said downwardly folded flanges, said downwardly folded flanges providing a protective cover for the pouring lip of the container and serving to retain the liftable parts in closed position for shipment and storage.

2. In a container having a pouring opening formed in the top wall thereof adjacent a corner edge of the container, a closure element for said pouring opening consisting essentially of an initially flat rectangular sheet of foil having dead-folding characteristics overlying said pouring opening and having one corner thereof adhesively secured to the top wall of the container inwardly of said pouring opening by a glue area the base edge of which defines a line of fold for said closure element, said line of fold forming a dead-folding hinge for said closure element when said element is opened and closed, the edges of said sheet of foil opposite the hinged corner thereof extending outwardly beyond the top wall of the container along the edges thereof adjacent said pouring opening, said last named edges of said top wall defining a pouring lip for the container, the extending edges of said sheet of foil being folded downwardly and juxtaposed to marginal edge portions of the adjoining container body walls, the downwardy folded portions of the foil sheet defining between them an extending gusset at the corner of the container which is folded to lie along one of said downwardly extending portions, the said downwardly extending portions providing a protective flange for the pouring lip of the container and serving to retain the closure element in closed position for shipment and storage, the said top Wall of the container being composed of a pluraliy of closure flaps including an inner closure flap having said pouring openings formed therein and an outer closure flap having a liftable portion thereof overlying said pouring opening, the outer edges of said liftable portion coinciding with the edges of the top wall adjacent said pouring opening, the said foil sheet being adhesively secured to said liftable portionso as to constitute said liftable portion a part of said closure element, said liftable portion being articulated to said outer closure flap along a line of fold coinciding with the hinge line in said foil sheet, whereby the deadfolding characteristics of said foil sheet are imparted to said liftable portion and said liftable portion serves as a reinforcement for said foil sheet.

References Cited in the file of this patent UNITED STATES PATENTS 1,956,217 Booth Apr. 24, 1934 2,146,226 Punte 1- Feb. 7, 1939 2,182,818 *Murch Dec. 12, 1939 2,197,739 Bensel Apr. 16, 1940 2,317,355 Bensel Apr. 27, 1943 2,321,011 Cox et a1 June 8, 1943 2,340,651 Denison Feb. 1, 1944 2,435,155 Palmer I an. 27, 1948 2,493,671 Homing Jan. 3, 1950 2,549,048 Bergstein Apr. 17, 1951 2,570,266 Nordquist Oct. 9, 1951 2,604,252 Bergstein July 22, 1952 2,609,985 Reid et a1 Sept. 9, 1952 2,629,534 Reynolds Feb. 24, 1953 2,657,848 Norden Nov. 3, 1953 2,661,137 Reid et a1 Dec. 1, 1953 FOREIGN PATENTS 392,395 Great Britain May 18, 1933 

